Ideas for Kingdom Hearts x Persona crossover
by Angel of light darkness
Summary: Reposted with permission from TheIdeaGuy. Keyblades and Persona, an item of great power and a power of limitless potential, what wonders will come from these forces crossing paths
1. Chapter 1

_Would the others be alright?_

That was the only question you could think of as you laid on the ground while a storm continued overhead, your body unmoving as most of your strength had left you after battling the Masters.

Still, why did they single you out? You doubt you was anyone special, maybe they focused on you since you were healing and putting everyone to sleep?

Master Aced singled you out once he spotted you, you guess he still remembered that incident near the fountain. He was, terrifying.

The difference between a normal Keyblade Wielder and a Master was something you were already familiar with due to Master Ava, but this was different.

The presence he gave was that of a being several times his own size, and the smile he gave as you tried to defend yourself made it all the more worse. You threw everything you had and he beat you easily, while he barely broke a sweat, you would have fallen then and there if Master Ira hadn't interfered.

Though, considering you had to fight Master Ira not a few minutes later, it took away the gratitude you felt when the only reason you survived that fight was due to Master Aced interfering.

A strange role reversal.

Master Invi and Master Ava didn't even attempt a final blow, instead walking away when it was clear who the victor was, both telling you to live on beyond this.

And Master Gula? You never saw him throughout this, you knew he was somewhere close even though you never saw him.

You tried to push myself up only to bring on a violent coughing fit, You think something came up with that cough.

Everything was cold. Your armour felt heavier than usual, you had a feeling it was a lost cause to repair it. You really liked your Leopardos, at least you used to, before all of this.

_Is, is this the end?_

It's becoming harder to keep your eyes open.

Trying again, you were able to roll yourself onto your back despite the hindrance your armour caused, as you looked up into the sky you could still see Hearts floating into the sky.

Hearts belonging to your friends.

Did you save anyone by coming here, or have you only walked with them into Darkness?

Your vision begins to blur as you tried to get up again.

"It's alright. You've done enough"

Your heard Chirithy's voice off to your side, the sadness in their voice was painful to hear.

Their the only friend you have left here, always by your side ever since you became a Keyblade Wielder.

You hugged Chirithy, seeing as this may be the last time your able to do it. Their crying seemed to overtake the rain as you hugged for the last time.

You patted Chirithy's head as you looked up at the sky, knowing that you aren't alone giving you some comfort.

The clouds parted as to reveal a bright light above you, seemingly as radiant as the sky but not blinding. If you squinted you could see a moon in the shape of a Heart, with the Hearts of your friends flouting up to it.

_Was it your time?_

Not a moment after you thought that did someone approach and knelt down besides you, even though you could only see a silhouette you knew in your Heart who was here.

_Skuld…_

It's becoming harder for you to stay conscious, you think Skuld said something but your unable to hear it. She steps back as someone else knells down besides you, though you can't see their face, the red scarf and your Heart told you who it was.

_Ephemer. We made, a promise. You're late._

You reached out to take his hand, and leave this place with them. Will the others-

You felt weightless, you look around and see a blue sky that seemed to drag on forever with water reflect the sky like a mirror. Within that reflective water you saw yourself as a butterfly.

You felt at peace, as if all your previous burdens were stripped away and left you free.

But.

Even though you wanted to stay in this place, you knew you needed to leave. There were others who needed you, though who or for what reason your unsure.

You fell into the water below, the deeper you dove the darker it became as the light from above became lost to the waves.

Even so, you felt something guiding you. Guiding you back to where you were needed, though it started to grow weaker the more you pulled at it.

You see something in the expanse, a platform with six pillars holding up a dome roof. You see someone there, standing at it's center.

You approach the structure and the person, once you have enter the person turns to you.

"Ah, welcome. It's a pleasure to meet you, it's rarity for anyone to meet me in here in this Realm Between. I am Philemon, a dweller of the Realms Between" the person introduced themselves to you with a polite tone, they seemed interested in something.

You greeted Philemon back, saying that it's a pleasure to meet him as well.

"And now, a simple test. Can you state your name?"

Name?

_Haru, your name is Haru._

The moment you spoke aloud your name you felt that weightlessness leave you, you looked down and saw your body wearing the clothes you'd normally wear.

"Splendid. There aren't many who can remember their identity, when in this domain, even those who wield a Keyblade of Heart"

Philemon said with the politeness still in his voice, though you were able to hear something else in it. Respect? Amusement? Surprise?

"It seems you pass that test, a test few truly pass. You have a firm grasp on your identity, I respect your strong will. In return, I grant this power"

Philemon outstretch his hand and in it appeared a crystal statue.

"Persona. It is the power to summon the numerous selves within yourself, the selves infused with divine love and the selves capable of demonic cruelty, the selves to guard your Heart and the selves to help you connect with others"

The crystal statue flouted towards as Philemon folded his arms.

"The time will come when you will need this power, to undo the mistakes of the past to protect the future's light. Now, it is time for you to return to your proper time and proper place"

_Will you ever meet him again?_

Philemon nodded "Perhaps, if you are in dire need of advice then know I will be available for counsel"

_Awesome! You'd hate it if you weren't able to meet up with a friend you just made later._

Philemon tilted his head

"A friend? You consider me a friend, despite us only just meeting"

_Of course, he's already done so much for you it's hard not to consider him a friend._

Philemon chuckled.

"You are certainly an interesting child"

_Uh, how do you get back to your proper time and proper place?_

"All you need to do is open the door that stands in your way"

Turning around, you saw a door with a velvet blue glow. Seeing that it was likely your only way back you summoned your keyblade and pointed at the door.

"You will encounter many obstacles in the future, and it's unlikely they can be overcome with a key, a blade or with magic"

Philemon said, causing you to lower your keyblade.

_What about something that's all three?_

"Especially something that is all three, often times the Heart, Mind and Soul are what will allow aid you to overcomes the things that block your path"

You dismissed your Starlight Keyblade and pushed on the door, it opened without resistance as you were washed with light.

When the light faded, you were in a place you didn't know with Chirithy crying into your chest as you laid down on a table. You looked over to see Skuld and Ephemer crying as well.

You patted Chirithy's head as you gave your friends a thumbs up.

_Hey, everything will be OK._

The shock followed by the relief and joy on their faces were priceless.

Author's notes:

_This means the viewpoint character is talking._


	2. Chapter 2

You open your eyes slowly, the awareness of your surroundings slowly returning with consciousness. Rubbing your head you find yourself on the ground on your back, you get off slowly as you feel a stiffness in your body, you look around to gauge your surroundings.

You found yourself in a darkened forest, the trees wilting as red clouds circled overhead, the area is unsettling quiet as no animals could be heard nor a breeze.

You get to your feet slowly, being careful not to fall over due to the stiffness in your limbs, you look around to get a sense of the immediate area.

"Ephemer, Skuld, are you out there!" You yelled, calling out to your friends who you were with not moments ago. Though, for some strange reason you can't remember what exactly the three of you were doing.

"Any idea what's going on Chirithy?" you asked aloud, hoping they'd have any ideas on what to do. When the only answer you received was silence, you began to worry "Chirithy?" you looked around but saw no sight of your little friend.

You continued to call out to Chirithy, worry became more apparent in your voice, as you looked everywhere around you. Spinning in place and checking the top of your head, looking into nearby trees and bushes, to try and find your (hopefully) hiding constant companion.

It isn't long until you accept that Chirithy is gone, meaning your all alone in an unknown forest in a potentially unknown world.

You summoned your Keyblade to open a doorway of Light but when you raise your hand you see that it isn't there, you tried again several times performing various gestures and saying whatever you think you bring out your Keyblade.

Nothing works.

Your lost, alone, and without your primary means of travel and defense.

Hoping for anything you put your hands together and channel magic into them, pulling them apart you are relieved to see an elemental orb. Meaning you weren't completely defenseless.

You look around deciding on where you go, there's no path or tail, you only see trees and grass with no hint as for where you go.

"May your Heart be your Guiding Key" You said to yourself before closing your eyes and spinning in place, stopping when you feel you should and walking that direction.

Seeing as you couldn't have any higher ground to give you some perception of the area, and the trees were so rotten that they couldn't support you weight, you had little other options beyond walking and hoping for the best.

The forest seemed to keep going on, the trees themselves seemed to fade into existance the further you walked and as those you walk away from fade like, a thick fog was blanketing the area making visibility beyond a certain point impossible.

Still, you continue on the path your Heart led you. And what you found broke it.

The fog and forest ended as you found yourself on a cliffside overlooking Daybreak Town. a true home for all Keyblade Wielders, fallen to ruin as most of the buildings were either heavily damaged or destroyed entirely.

You aren't sure how long you stood there, looking on in shock, but when you regained your wits you looked for a path from the cliff to the town. Once you found one you ran towards your second home to see what had gone terrible wrong.

When you arrive in Daybreak Town you find it completely deserted, the once busy streets and stores now empty, the more you search the town the more evidence you uncover of what happened. There were area with signs of intense fighting, slashes into walls or marked with the sign of magic being used.

It was clear that Daybreak Town was the site of a grueling battle that had left the once welcoming and comforting town a shadow of its former self.

It pained to see it in such a state, but you soldier on to try and find out where everyone was and figure out why you have no memory of what happened here.

You searched everywhere you could and found nothing, as you trudged along you spotted the fountain you frequent regularly in Daybreak Town's square. It was covered in cracks and the water was gone.

You sat down, dejected at not finding anyone in your search, the feeling of isolation in a place so familiar to you taking away what joy your memories held.

"Where is everyone?" you asked yourself as you sat on one part of the fountain that didn't look like it would fall apart if you sat on it.

"You already know where they are"

"Chirithy!" You shouted in delight at the voice of your friend beside you, you jumped to your feet and picked them up to hug them.

You hugged Chirithy as much as you could, without hurting them of course, as you placed your head on top of them. Feeling the teddy bear like fur Chirithies were known to have.

But.

As you hugged Chirithy you felt something was, different.

Looking down, what you see isn't Chirithy.

Were a normal Chirithy was white and grey with black stripes with sleepy blue eyes, the one in your arms was a dark purple and orange with wide red eyes.

A spike of pain pierces your head, causing you to clutch your head in an attempt to somehow lessen the pain.

'Let's meet again, in another dream'

In that moment, the parade of Hellish memories overcame you.

The clash of Keyblade against Keyblade, rivalries meant to push one another to greater heights turned into feuds that sought the destruction of the other, a world once filled with Light ripped apart as those who swore to protect it destroyed each other and the home they all shared was the location of the first blows.

"Keyblade. War?"

You fell to your knees, your strength leaving as the memories returned to you.

"This, this isn't really Daybreak Town" You said as your tears fell.

"No" Nightmare Chirithy in your arms answered "I'm not sure what this place is, all I know is that it is overflowing with the negative emotions and memories of those from the Unions.

All you could offer was a non-verbal agreement, something that was half sobbing, as it seemed like the fight that took place in Daybreak Town was happening again around you with Phantoms of everyone.

"It's painful, those memories. Even with my efforts to severe our bond I can still feel the ache in your Heart" Nightmare Chirithy said "I'm guessing you'd want that pain to go away"

"No"

You said between sobs, that one word seemed to cause everything to come to a stand still. Nightmare Chirithy looks up at you confused.

"It's painful, yes, but it doesn't change the fact that it happened. I-If their really gone then there's not much I can change that, I have to move forward with their memory in my heart. The good and the bad, because if I only remember the good then I won't remember them but an incomplete version. A false facility"

"You mean facsimile" Nightmare Chirithy said, going quiet as they lowered their head.

You nodded "Yeah" you look down at Nightmare Chirithy in your arms "Heh, I think this is the longest we have had a conversation between one another"

Nightmare Chirithy raised to say something, but whatever words they were about to say died as they spotted something "Look out!"

You spun in place to see what Nightmare Chirithy saw, several silhouettes of Keyblade Wielders approached you ignoring whatever event they were reenacting.

The closer they approach you begin to hear voices in your head, phantom pains begin dancing all over your body and only grow worse the closer they come.

"These things, these Shadows. They're able to force emotions and past sensations onto you, the shorter the distance the more effective it is" Nightmare Chirithy jumps from your arms and onto the fountain "You better make a run for it"

You look around for an escape route but only seeing these Shadows already have you completely encircled, you grit your teeth and prepare a fireball to throw give you a chance to escape.

You were going to fight on, not just for yourself but for others, those who remain and for those no longer.

As those words echo in your mind a surge of power came forth, pushing back the negative emotions and experiences the Shadows were forcing on you.

That power surge outward into a blue mist that rose above as something began to materialize.

One of the Shadows leaped at you with it's weapon pointed at you, before it could reach you it was set aflame and cut in half.

"I am Thou, and Thou art I. From the Sea of thy Soul I cometh, my blade shall be forever at your side"

You looked on in awe as the knight above you fought the Shadows that got near you, even after the Shadows that approached you transformed into monstrous creatures.

Seeing a Shadow trying to sneak up on Gawain, you don't know why but you feel the being that came from you soul is named Gawain, so you launch an Orb of Water at the creature only for it to hit an invisible barrier and sent right back to you. You barely dodged as it hit one of the nearby windows.

Gawain helps you up, after dealing with the attacking enemies, as the previous onlooking silhouettes began to twitch violently before flying into the air and gathering into a massive ball. As soon as no more Shadows were being drawn in it began to pulsate as it transformed into a human with long red tears streaks on its face, it released an inhuman roar that caused you to skid back as Nightmare Chirithy held onto the fountain for dear life.

"Stand fast, for you hold the power to overcome this challenge" Gawain spoke as they hovered above you.

"It'd be a lot easier if I had my Keyblade!" You yell as the inhuman roar continued, partially wondering how you were able to hear Gawain so clearly.

"All you must do is reach within yourself for it. But beware, in this realm it shall make you the enemy of all"

With those words you felt something on your chest, looking down you saw a Keychain coming out of it, you reached for it as the guard of a weapon came into view. Pulling it out you saw it was your Starlight Keyblade.

The giant in front of you saw it and roared anew. This time; it sounded human, twisted by pain and grief.

"Betrayal, Betrayal. BETRAYAL!"

You leapt into the air, Gawain besides you, as you fight the monster before you.

Once the final blow was struck, by a cross slash of your Keyblade and Gawain's sword, the giant fell to its knees as a light shined from it's chest and shot into the air. As it did the clouds parted, a blinding light shined through and covered you and everything around the fountain.

Once your eyes adjusted to the light you saw more Shadows approaching from one of the nearby streets leading to the square, you got ready for another fight as it drew nearer, but as it neared the light it turned away back from where it came. Looking around you saw the same thing in the other streets, those who were on the roofs and the Shadow creatures you now see soaring in the sky.

"Odd. it seems they can't enter the light, meaning you should be safe for the time being" Nightmare Chirithy said as they hopped down from the now fully restored fountain.

You turn to Nightmare Chirithy with a frown "Me? Then, what about you? Are they able to affect you?"

Nightmare Chirithy turned to you with a smug tone "I can get around just fine, I doubt these things can even register me"

You sigh in relief "That's good" you turn to Gawain, and as you do you begin to remember an odd dream, and give your Persona a smile. No words were needed between you two. Gawain nodded as it turned into a card and flouted down into your chest.

"What is that power anyway? It doesn't feel like anything I have come across" Nightmare Chirithy muttered before turning away from you "Well, I suppose you'll use your Keyblade to go wherever the survivors are"

You look at your Keyblade and over to the fountain, an odd idea coming to your mind "Maybe not, I think there is already a path open after defeating that thing. But first"

As quickly as you could you scooped up Nightmare Chirithy into your arms and began hugging them again "thanks for helping me"

Nightmare Chirithy begins squirming in your arms to get free "What!? When did I ever help you?"

"You warned me of the coming Shadows, if you hadn't I doubt I would have noticed them until it was too late" you answer with a smile as you sit on the edge of the fountain.

"Only because I would have been attacked too since you wouldn't let me go!" Nightmare Chirithy shouted back.

"Hey, do you want to come back with me? It'd get pretty lonely here since you can't really interact with anyone here" you asked, even as a part of you already knows the answer.

"No. I'd prefer to stay here, at least for now" With those words, you put Nightmare Chirithy down beside you on the fountain's edge.

"Okay, I'll be sure to visit as soon as I can. Maybe we can even explore this place together?" you offered and, not hearing any form of disagreement, patted Nightmare Chirithy's head.

===================================================================================

I am thou, thou art I  
Thou has reforged an old bond  
It shall be the key to crossing the boundary, Unlocking new power, and transcending limitations.  
With the Birth of the Jester, you shall receive its blessing.

You fall backwards into the fountain, and as you fall into depths deeper then it should be, as the red light of the other world becomes lost to the water a blue light shines over you.

You wake up in the world of Enchanted Dominion, with your regular Chirithy beside you.


	3. Ideas for combining powers

Keyblade [Kingdom Hearts] x Persona [Shin Megami Tensei Series] + Soul Devices [Tokyo Xanadu]

**How the powers could mix.**

While it might be due to my lack of comprehensive knowledge of Tokyo Xanadu, I don't see too much that's different from Persona. They don't have entities they summon in TX and with Persona Weapons being a thing in Persona already [Not to mention I am pretty sure P5 Hero got a knife when he first summoned his Persona], so I combined them together with Soul Devices being part of the Persona power and being renamed Soul Weapons.

That, and it helps add to the crossover of Persona x Kingdom Hearts.

**Now, some needed backstory/lore to set things up.**

In the Beginning, everything came from Kingdom Hearts. KH gave light and from that came life and with it people, from the Hearts of people Darkness was born. So pretty much canon lore for Kingdom Hearts with Light, Darkness, and Nothingness coming into existence.

The Collective Unconscious is formed by the People of The World, either as a means to connect with each other or a general means of survival. It's a realm where Concepts are in abundance, from Heroism to Villainy and Hope to Despair, while gaining power from these Concepts are easy they could gradually change a person if they lack a strong will. A place where Ideas/Concepts reign and emotions can be overshadowed.

The Collective Unconscious, or Sea of Souls, also acts as a repository history and knowledge. Containing what's essentially backups of people's personalities and knowledge, the more famous or exalted someone is in death the bigger influence they would have in the Sea of Souls and gain connects to concepts such as Heroism.

From the Collective Unconscious two Entities are born, The Embodiment of Self-Love Philemon and The Embodiment of Self-Hate, they natural clash with one another by are trapped in a stalemate due to them being too evenly matched so they mostly challenge each other through proxies. Usually with individuals with strong enough Minds to Wield Personas and Soul Weapons.

The Collective Unconscious soon becomes home to beings born from folklore and myths such as the Greek Pantheon, becoming fully realized beings able to interact with the physical world. This is a power of the Collective Unconscious where when enough people believe enough it could rewrite reality, both in minor and major ways with granting minor buffs/blessings through spread rumors or erasing the World itself.

The backups I mention that the Sea of Souls keep play a huge part with Nobodies.

Okay, when a Somebody [A Complete Person] has their Heart removed they leave behind a Heartless and a Nobody [if they're strong enough] The form a Nobody takes is dependent on how they saw themselves as a Somebody, Dusk the common enemy Nobodies are what a regular person would turn into while the other form of Nobodies would come about due to that Somebody seeing themselves fitting into a particular archetype or loosely fitting it.

If the Somebody has a strong enough grasp on who they are, they are able to retain their Somebody form without prior memories and being able to summon their Soul Weapon. But it is possible for these higher level Nobodies to be reduced to lower form of Nobodies by having their Mind attacked.

And with this setup it makes what happened to Sora in Kingdom Hearts 1 make a bit more sense, if we work on the idea that Heartless can immediately form after someone's Heart is removed but a Nobody takes time to form.

When Kairi hugged Sora as a Pure Heartless she unknowingly used the backup of Sora in the Sea of Souls to restore him to human form, while in the meantime Sora's Body is divided into two to form Namine and Roxas. Both coming into existence due to Kairi's Princess of Light Heart and a sleeping Ven inside Sora's Heart messing up the process so Kairi's, Sora's and Ven's backups each add something to the formation of the two since Kairi's Heart and Ventus's Heart were both inside Sora when he released his Heart.

It could also explain what happened to Ventus after Birth By Sleep as, although his Heart was gone, his Mind was still connected to his Body and his Heart hadn't fallen to Darkness allowing Ventus's Mind to hold onto his inactive body.

As for why Roxas, Namine and Xion don't have soul weapons the answer is relatively simple. Roxas and Namine couldn't form Soul Weapon natural since at around three Somebodies were involved with their creation and Xion was artificially created to be a backup Keyblade Wielder for The Fake Organization XIII.

_Again, corrections and discussion is encouraged to help flesh out this idea._

Right then, after the whole lore and headcanon dump, onto the powers. 

**Power Mixing and possible results**

Keyblades, Personas and Soul Devices are things that come from the user (in certain cases with the Keyblade) and are all connected to the Soul/Heart/Mind.

Keyblade Wielders gain enhanced magic abilities, conceptual locking and unlocking of anything the user can think up along with the other hax abilities.

Personas Users can summon Personas, their tamed Shadow that grant them various magic abilities along absorption/reflection/resistances to attacks, granting them an additional source of sensory input. Along with special powers in rare cases such as clairvoyance, passive regeneration or having multiple Personas.

Soul Devices/Soul Weapons, again not too familiar with Tokyo Xanadu so feel free to add or correct me, are weapons with affinities to certain attributes that take the shape of whatever weapon best suits it's wielder whether that's a whip sword gauntlet, a hammer with drone for long range attacks or a pair of wings. Soul Devices/Weapons are capable of close ranged combat with long range energy blasts, a charge attack that aids with getting pass large gaps with limited constructed of energy and energy clones.

Persona User x Keyblade Wielder

Due to how Persona Users could be considered Darkness users that Conquered their own inner Darkness I'd say they'd gain a high resistance to the corrupting elements of KH's Darkness, potentially immune if they achieved their Ultimate Persona.

Possibly having Personas able to automatically attack and defend the user, with more power for the Persona and Keyblade.

New Keyblade for each Social Link with Keyblade Armors for Maxed out SL.

More ease with controlling the forms the Keyblade can take.

Persona User + Soul Device.

As for how Soul Devices slot into the Persona power, I see it as the Persona user has a custom weapon that can grow with them and can channel different attribute attack if the have a moment to focus on changing it so as long as they know an attack with the attribute. They could also share some elements with Nil Weapons from Persona 3 were a Wild Card can insert certain Personas for special weapons.

Keyblades x Soul Devices.

Honestly, I just picture this set up would function just like how Lea/Axel uses his Keyblade and Nobody signature weapons. Along with flight similar to what we see Sora use in KH1 or Master Xehonart in KH3.

Keyblade x (Persona + Soul Devices)

Now here's the meat and potatoes, everything from above is included here and enhanced with a new power.

Merged Form. A Super Mode that combines Keyblade armor, Soul Weapon and Persona for a monstrous increase in all parameters that can be perfected once a person understands themselves, or gain the World Arcana from Persona.

So, that's about my idea on how I think these powers could work together.


End file.
